Driving down a mounain Jim finds that he has descended 1800FT in elevation by the time he is 3.25 mi horizontally away from the top of the mountain find the slope of his decent to the nearest hundreth.

I am sorry that you did not get a response to your post earlier.

You need to use the same units. Convert 3.25 miles to feet, noting that there are 5280 feet in a mile. Then divide that into 1600 to get the slope. Since it is decreasing rather than increasing, you need to remember that the slope is negative.